- EV motors are becoming smaller, more efficient, and less reliant on rare earth materials
- Innovations like hairpin windings and contactless rotor excitation improve performance and durability
- High-voltage systems and advanced cooling methods are transforming electric powertrains
The Next Big Thing in EVs Might Be Inside the Motor
Electric vehicles have always been associated primarily with batteries. When people talk about the future of electric mobility, they're usually focusing on how big the batteries are, their charging speeds, driving range, and the chemistry inside those cells. But, interestingly enough, there's a big shift happening deeper down in the drivetrain, right inside the electric motor itself.
According to Focus, the latest versions of electric powertrains are getting smaller, more powerful, and way more efficient. Some of these new units are achieving conversion efficiencies of up to around 95 percent.That number is important because how efficient a motor is directly influences how well electrical energy gets turned into motion. When less energy gets wasted during that process, the EV can make better use of the battery it already has.
Now, this development isn’t just an isolated tweak, no, it has broad impacts across the whole EV industry. Batteries are still the most expensive and heaviest module in an EV, and making them bigger just adds weight. A smarter, more efficient motor can help manufacturers avoid relying solely on larger battery packs to improve performance or extend driving range.
Moving Away from Rare Earth Materials
One of the most notable changes? Shifting away from permanent-magnet motor designs that rely on rare earth materials.
The US Department of Energy’s Transportation Technologies Office supports research aimed at reducing dependence on these materials. The three primary motor types used in hybrid and plug-in electric vehicles are permanent-magnet, induction, and switched-reluctance motors. Each has its own pros and cons when it comes to efficiency, complexity, material needs, and production.
Permanent-magnet motors have played a big role in EVs, but their dependence on rare earths raises supply concerns. Focus reports that more manufacturers are switching to externally excited synchronous motors. These use switchable electromagnetic fields rather than permanent magnets.
This difference isn’t just technical; it affects the supply chain. Motors that don’t rely on permanent magnets can reduce dependence on rare earth materials and the suppliers associated with them, particularly in Asia.
Hairpin Windings and Manufacturing Advances
The internal structure of the motor itself is also changing. Focus states that newer systems are transitioning from traditional round-wire windings to hairpin technology. In this process, rigid copper bars are inserted and automatically welded into the stator.
Hairpin technology raises the copper fill factor from less than 50 to more than 70 percent. More copper means the motor can carry more current and shed heat more effectively. As a result, smaller motors can produce the same power output.
Contactless Rotor Excitation: Less Wear, More Durability
Another innovation described by Focus is contactless rotor excitation. Earlier externally excited synchronous motors used slip rings, which created wear. Modern versions from suppliers of ZF or Mahle transfer the current for the rotor’s magnetic field inductively, without physical contact.
The approach can also reduce dependence on rare earths such as neodymium and dysprosium. At highway speeds, the rotor’s magnetic field can be switched off or weakened, helping maintain efficiency.
Silicon Carbide and High-Voltage Systems
The rest of the drive system is also changing fast. Focus describes how silicon carbide semiconductors and 800V architectures can reduce losses, lower cable weight, and enable charging speeds of more than 400kW in some applications.
The inverter controls how electricity moves from the battery to the motor. Silicon-carbide MOSFETs can switch at up to 50kHz and reduce heat losses by up to 70 percent, according to Focus. The article says this can increase an EV’s range by five to seven percent.
An 800V system allows the same power to be delivered at half the current. That can reduce cable cross-sections, save weight, and lower thermal stress.
Cooling Gets More Critical at Higher Speeds
The motor also needs more cooling as speeds go up, including direct oil-cooling methods. Modern electric motors can reach speeds of up to 20,000rpm or more, making thermal management increasingly important.
Instead of cooling only the stator with a water-glycol jacket, newer systems pump synthetic oil directly into the rotating shaft. Centrifugal force then directs it toward the stator windings and rotor assembly. This helps prevent demagnetization and performance losses during sustained high-speed driving.
Mercedes’ Bold Move – Axial-Flux Motors
Mercedes is particularly proud of its axial-flux motors, which are used in high-performance electric models such as the AMG GT four-door and SUV. These vehicles can produce more than 850kW. The underlying axial-flux principle was developed by British electric-motor manufacturer YASA, which now belongs to Mercedes.
In an axial-flux motor, electromagnetic flux runs parallel to the motor’s axis of rotation. Key components are designed as thin discs, with rotors sandwiching the stator from both sides.
In an AMG GT four-door or AMG SUV, the front-axle drive is around nine centimeters wide, while the two rear motors are each only 8cm wide. Peak output reaches up to 860kW or 1,169hp, with possible output of up to 1,000kW or 1,360hp. The motors turn at up to 15,000rpm at top speed.
The Race Evolves Beyond Just Batteries
The message for suppliers and buyers in the EV space is clear, it’s no longer just about how big your battery pack is. Now, it’s also about who can develop the most efficient, resource-light motor systems.
Battery technology remains crucial, but motor efficiency determines how effectively stored energy is converted into movement. Smaller motors, alternative motor types, improved power electronics, advanced cooling, and higher-voltage systems are reshaping electric powertrains alongside battery development.
Quick Takeaways
- - Modern EV motors are shrinking, getting stronger, and achieving efficiencies of up to around 95 percent.
- - Externally excited synchronous motors can reduce dependence on rare earth materials.
- - Hairpin windings increase copper fill and enable smaller motors.
- - Silicon carbide semiconductors and 800V systems can reduce losses and support faster charging.
- - Direct oil cooling helps motors handle higher speeds and thermal demands.
- - The competition now hinges on motor design, manufacturing, and efficiency, not just battery size.
Disclaimer: This article may have been created with AI assistance and reviewed by our editorial team. It is provided for general informational purposes only. Readers should verify information independently before relying on this content.
